Neurosurgery. 1993 May;32(5):841-3; discussion 843.

Arachnoid cyst of the lateral ventricle manifesting positional psychosis.

Wong CW1, Ko SF, Wai YY.

• 1Division of Neurosurgery, Chang Gung Memorial Hospital, Taipei, Taiwan, Republic of China.

Abstract

A 30-year-old woman had an arachnoid cyst in the trigone of the right lateral ventricle 5 years before she developed episodic auditory and visual hallucinations as well as delusions of persecution. The psychotic episodes tended to occur after the patient had lain in bed for 1 to 2 hours. After craniotomy and wide excision of the cystic membrane, draining the cystic fluid to the lateral ventricle, the psychotic episodes subsided in a follow-up period of 6 months. We believe that when the patient was recumbent, the trigone cyst blocked the temporal horn further, caused local ischemia, and triggered the psychosis, which was a form of partial complex psychomotor seizure.

PMID:  8492862